In this situation, a small, floating lure, soft plastic bait or crankbait would be a much better option, as they would allow you to stealthily search out the water column without the risk of getting snagged on the bottom
For a line of the sort of breaking strain and diameter that we use for carp fishing to deteriorate to the extent that it will snap easily is an extreme case, but you will definitely notice a deterioration in the performance of the line in other areas if you dont change it fairly regularly whilst regular usage is one factor in that, age also comes into play even if it has just been sat on your reel not being used for an extended period of time
I'd check eBay
Periodical care is about maintaining the smooth reliable operation of the reel, reducing wear, as well as protecting it from corrosion
Specifications: Model Line Capacity Weight Diameter RX1 3/4/5 WF5+(50yds20#) 3.7 oz
The internal motor pulls a wire or a gear that causes the jointed sections of the lure to kick back and forth